<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>CSS选择器</title>
    <style>
        #d1{
            color:red;
        }
        #d2{
            color:green;
        }
        #d3{
            color:blue;
        }
        .c1{
            color: #7937ff;
            background-color: #ddb9b2;
        }
        div{
            color: yellow;
            width: 300px;
            height: 100px;
        }
        *{
            font-size: 30px;
        }
    </style>
</head>
<body>
<div id="d1" class="c1">第1个div</div>
<div id="d2" >第2个div</div>
<div id="d3" class="c1">第3个div</div>
<!--<p>这是一个段落</p>-->
</body>
</html>